Clinicopathologic relevance of asymptomatic endometrial carcinoma

OBJECTIVE: To assess whether screening asymptomatic women is significant for early detection of endometrial carcinoma. STUDY DESIGN: We compared the clinicopathologic findings and prognoses of 21 asymptomatic patients with 427 symptomatic patients with endometrial carcinoma. RESULTS: The incidence of asymptomatic endometrial carcinoma was 4.7%. Nineteen of 21 asymptomatic patients with endometrial carcinoma were found by cytologic screening for endometrial cancer. There was a statistical difference in the histopathology and depth of myometrial invasion between the asymptomatic and symptomatic groups. However, no statistical differences were found in tumor grade, lymph node metastasis, adnexal metastasis, cervical invasion, peritoneal cytology, surgical stage and patient age. Univariate analysis showed that the presence or absence of symptoms was not related to survival. CONCLUSION: The detection of asymptomatic endometrial carcinoma is not related to a reduced mortality rate. Screening asymptomatic women for endometrial carcinoma is not recommended.     

T cells of atopic asthmatics preferentially infiltrate into human bronchial xenografts in SCID mice

T cells play an important role in the pathogenesis of bronchial asthma. However, it is not completely known how circulating lymphocytes infiltrate into the airways of asthmatic patients. Because SCID mice are unable to reject xenogenic transplants, many xenotransplant models using various human tissues have been developed. Therefore, to examine the interaction between bronchi and T lymphocytes of asthma, it may be possible to use the human bronchial xenograft and PBMC xenograft in SCID mice. We transplanted human bronchi into the subcutaneum of SCID mice and i.p. injected PBMCs that were obtained from patients with atopic asthma, atopic dermatitis and rheumatoid arthritis, and normal subjects (asthmatic, dermatitis, rheumatic, and normal huPBMC-SCID mice). There was no difference in the percentage of CD3-, CD4-, CD8-, CD25-, CD45RO-, CD103-, and cutaneous lymphocyte Ag-positive cells in PBMCs among the patients with asthma, dermatitis, rheumatoid arthritis, and normal subjects, and CD3-positive cells in peripheral blood of asthmatic, dermatitis, rheumatic, and normal huPBMC-SCID mice. The number of CD3-, CD4-, and CD8-positive cells in the xenografts of asthmatic huPBMC-SCID mice was higher than those of dermatitis, rheumatic, and normal huPBMC-SCID mice. IL-4 mRNA and IL-5 mRNA were significantly higher in the xenografts of asthmatic huPBMC-SCID mice than those in the xenografts of normal huPBMC-SCID mice, but there were no significant differences in the expressions of IL-2 mRNA or IFN-gamma mRNA between them. These findings suggest that T cells, especially Th2-type T cells, of asthmatics preferentially infiltrate into the human bronchi.     

DNA damage response pathway in radioadaptive response

Radioadaptive response is a biological defense mechanism in which low-dose ionizing irradiation elicits cellular resistance to the genotoxic effects of subsequent irradiation. However, its molecular mechanism remains largely unknown. We previously demonstrated that the dose recognition and adaptive response could be mediated by a feedback signaling pathway involving protein kinase C (PKC), p38 mitogen activated protein kinase (p38MAPK) and phospholipase C (PLC). Further, to elucidate the downstream effector pathway, we studied the X-ray-induced adaptive response in cultured mouse and human cells with different genetic background relevant to the DNA damage response pathway, such as deficiencies in TP53, DNA-PKcs, ATM and FANCA genes. The results showed that p53 protein played a key role in the adaptive response while DNA-PKcs, ATM and FANCA were not responsible. Wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K), mimicked the priming irradiation in that the inhibitor alone rendered the cells resistant against the induction of chromosome aberrations and apoptosis by the subsequent X-ray irradiation. The adaptive response, whether it was afforded by low-dose X-rays or wortmannin, occurred in parallel with the reduction of apoptotic cell death by challenging doses. The inhibitor of p38MAPK which blocks the adaptive response did not suppress apoptosis. These observations indicate that the adaptive response and apoptotic cell death constitute a complementary defense system via life-or-death decisions. The p53 has a pivotal role in channeling the radiation-induced DNA double-strand breaks (DSBs) into an adaptive legitimate repair pathway, where the signals are integrated into p53 by a circuitous PKC-p38MAPK-PLC damage sensing pathway, and hence turning off the signals to an alternative pathway to illegitimate repair and apoptosis. A possible molecular mechanism of adaptive response to low-dose ionizing irradiation has been discussed in relation to the repair of DSBs and implicated to the current controversial observations on the expression of adaptive response.     

Monitoring of urine nitric oxide (NO) related substrates and immunological competence in hematological malignancy

It has been reported that concentrations of neopterin in the urine are changed according to the host immunological conditions. In the present study, we measured urinary concentration of neopterin in patients with malignant hematological disorders and investigated the relationship between urinary neopterin levels and laboratory indices for cellular immunity. Urine neopterin levels were correlated with serum sIL-2R levels in the patients with malignant lymphoma, and inversely correlated with lymphocyte reactivity with ConA in the patients with acute myelocytic leukemia. However, no significant correlation was observed between urine neopterin levels and lymphocyte reactivity with phytohemagglutinin and pokeweed mitogen, CD4/8 ratio, CD56+ 16+ subset or serum IFN-gamma levels. In the patients with malignant lymphoma, parallel changes in serum sIL-2R and urine neopterin were observed. The presented results suggest that urine neopterin levels are related to the activation of T cells in malignant lymphoma.     

Comparison of investment in nest construction by the foundresses of consubgenericPolistes wasps,P. (polistes) riparius andP. (P.) chinensis (hymenoptera, vespidae)

Some metric characters of nests built during the founding phase by foundresses were compared between two consubgenericPolistes wasps,P. (Polistes) riparius andP. (P.) chinensis, the former of which inhabit higher latitudes. Volumes and dry weights ofP. riparius nests were strikingly larger than those ofP. chinensis, even when standardized by the foundress weight (2.5 times for volume and 2 times for weight), showing that foundresses ofP. riparius invest much more in the nest construction than those ofP. chinensis. However, percent weights of oral secretion used for nests to total nest weights were smaller inP. riparius than inP. chinensis (52.1% vs. 60.4%). The differences in the investment by foundresses of the two species in the construction and maintenance of nests were discussed in relation to climatic and other environmental factors.     

An rne-1 pnp-7 Double Mutation Suppresses the Temperature-Sensitive Defect of lacZ Gene Expression in a divE Mutant

A divE mutant, which has a temperature-sensitive mutation in the tRNA₁^Ser gene, exhibits differential loss of the synthesis of certain proteins, such as β-galactosidase and succinate dehydrogenase, at nonpermissive temperatures. In Escherichia coli, the UCA codon is recognized only by tRNA₁^Ser. Several genes containing UCA codons are normally expressed after a temperature shift to 42°C in the divE mutant. Therefore, it is unlikely that the defect in protein synthesis at 42°C is simply caused by a defect in the decoding function of the mutant tRNA₁^Ser. In this study, we sought to determine the cause of the defect in lacZ gene expression in the divE mutant. It has also been shown that the defect in lacZ gene expression is accompanied by a decrease in the amount of lacZ mRNA. To examine whether inactivation of mRNA degradation pathways restores the defect in lacZ gene expression, we constructed divE mutants containing rne-1, rnb-500, and pnp-7 mutations in various combinations. We found that the defect was almost completely restored by introducing an rne-1 pnp-7 double mutation into the divE mutant. Northern hybridization analysis showed that the rne-1 mutation stabilized lacZ mRNA, whereas the pnp-7 mutation stabilized mutant tRNA₁^Ser, at 44°C. We present a mechanism that may explain these results.     

Influence of protein flexibility on the redox potential of rubredoxin: Energy minimization studies

A theoretical investigation of the protein contribution to the redox potential of the iron–sulfur protein rubredoxin is presented. Structures of the oxidized and reduced forms of the protein were obtained by energy minimizing the oxidized crystal structure of Clostridium pasteurianum rubredoxin with appropriate charges and parameters. By including 102 crystal waters, structures close to the original crystal structure were obtained (rms difference of 1.16 Å), even with extensive minimization, thus allowing accurate calculations of comparative energies. Our calculations indicate an energy change of about –60 kcal/mol (2.58 eV) in the protein alone upon reduction. This energy change was due to both the change in charge of the redox site and the subsequent relaxation of the protein. An energy minimization procedure for the relaxation gives rms differences between the oxidized and reduced states of about 0.2 Å. The changes were small and occurred in both the backbone and sidechain mainly near the Fe–S center but contributed about – 16 kcal/mol (0.69 eV) to the total protein contribution. Although the neglect of certain effects such as electronic polarization may make the relaxation energies calculated an upper limit, the results indicate that protein relaxation contributes substantially to the redox potential. © 1993 Wiley-Liss, Inc.     

Voltage-dependent inhibition of the sodium pump by external sodium: Species differences and possible role of the N-terminus of the α-subunit

Currents generated by the Na⁺/K⁺ ATPase were measured under voltage clamp in oocytes of Xenopus laevis. The dependence of pump current on external [Na⁺] was investigated for the endogenous Xenopus pump as well as for wild-type and mutated pumps of electroplax of Torpedo californica expressed in the oocytes. The mutants had -subunits truncated before position Lys²⁸ (K28) or Thr²⁹ (T29) of the N-terminus. The currents generated by all variants of pump molecules in the presence of 5 mM K⁺ show voltage-dependent inhibition by external [Na⁺]. The apparent K₁ values increase with membrane depolarisation, and the potential dependence can be described by the movement of effective charges in the electrical potential gradient across the membrane. Taking into account Na⁺-K⁺ competition for external binding to the E₂P form, apparent K₁ values and effective charges for the interaction of the Na⁺ ions with the E₂P form can be estimated. For the Xenopus pump the effective charge amounts to 1.1 of an elementary charge and the K₁ value at 0 mV to 44 mM. For the wild-type Torpedo pump, the analysis yields values of 0.73 of an elementary charge and 133 mM, respectively. Truncation at the N-terminus removing a lysinerich cluster of the a-subunit of the Torpedo pump leads to an increase of the effective charge and decrease of the K₁ value. For K28, values of 0.83 of an elementary charge and 117 mM are obtained, respectively. If LyS²⁸ is included in the truncation (·T29), the effective charge increases to 1.5 of an elementary charge and the apparent K₁ value is reduced to 107 mM. The K, values for pump inhibition by external Na⁺, calculated by taking into account Na⁺-K⁺ competition, are smaller than the K_/12 values determined in the presence of 5 mM [K⁺]. The difference is more pronounced for those pump variants that have higher K_m, values. The variations of the parameters describing inhibition by external [Na⁺] are qualitatively similar to those described for the stimulation of the pumps by external [K⁺] in the absence of extracellular [Na⁺]. The observations may be explained by an acess channel within the membrane dielectric that has to be passed by the external Na⁺ and K⁺ ions to reach or leave their binding sites. The potential-dependent access and/or the interaction with the binding sites shows species differences and is affected by cytoplasmic lysine residues in the N-terminus.     

Three kinds of extracellular glucosyltransferases from Streptococcus mutans 6715 (serotype g)

In addition to the 1,3-alpha-D-glucan synthetase (pI 4.9) and the highly-branched 1,6-alpha-D-glucan synthetase (pI 3.9-4.1), Streptococcus mutans 6715 (serotype g) was found to secrete the third glucosyltransferase in multiple forms (pI 5.5-7.0), which exhibited 87% 1,6-alpha-bond-, 6% 1,3-alpha-bond- and 7% 1,3,6-branch-forming activities. The production of this enzyme was extremely enhanced when the organism was grown in Tween 80-supplemented medium. The 3 glucosyltransferases from the same organism were enzymatically and immunologically distinct from each other, and they were commonly found among the serotype g strains.     

Tapping culture-an improved method for cell suspension culture

Summary A new culture vessel was designed for cell suspension culture. A silicone-convered magnet bar fixed by one end to the side wall of the bottle was held horizontally a short distance from the bottom. A standard type magnetic stirrer was used. In contrast to the conventional horizontal movement of “stirring” in cultures the bar moves vertically with a “tapping” motion. This improvement resulted in less cell injury, higher rate of cell proliferation and formation of fewer bubbles than in the conventional type. Nine cell types were simultaneously cultivated in tapping, stirring and stationary culture. All cell types proliferated more luxuriously in tapping cultures than in stirring cultures. Serial cultivation of cells in tapping cultures was also successful. This work was supported in part by the grants for Cancer Research from the Ministry of Education, Science and Culture, Japan.